The Analyses For The Ore-controlling Structure Of JiZiping Golddeposit In Pingwu County, Sichuan Province

Ji Ziping gold deposit is located in the Yangtze block, the joint of the middle and orogenic zones of Hoh Xil--Bayan Har and the Motianling, also the north of north-east tectonic belt on Longmen Mountains, and the Qingchuan great fault on NEE is connected with the east-west tectonic belt on Motianling, the south-west is Jiaoziding brachyanticline. It belongs to the metallogenic sub belt of Artillery range on the southern margin of the Motianling metallogenic belt which is on the "Sichuan, Gansu, Shanxi" Golden Triangle metallogenic region. The ore bodies mainly occur in the gray sericite phyllite and quartz phyllite which are on the upper rock group of the upper part of sub group in the Silurian System of Maoxian group.This paper is based on the full collection and analysis of previous studies and research results. Also, in-depth and detailed field survey, data collection and indoor analysis have been made for it. By relying on the theory of plates and starting from the tectonic geology, we have made use of structural geology, petrology, mineralogy, geochemistry, ore field theory and other theories to study the relationship among strata, tectonics and mineralization. We have also analyzed the geological features of the deposit in ore districts, the geological tectonic evolution and the various ore-controlling factors to demonstrate the space-time relationship between tectonics and mineralization, and then to summarize the metallogenic regularity.According to the study, the formation of the gold deposits in this area is strictly controlled by the fault structure. For the different form and position of forming the ores, the ore types are mainly altered phyllonite type and quartz vein type. And the altered phyllonite type is the main type of the Ji Ziping gold deposit. According to the paragenetic association of minerals, the structural characteristics, the intercalated relationship of vein material and the sequence of mineral formation, the mineralization stage is divided into tectonic hydrothermal period and the supergene period, which are specifically divided into 5 stages.By studying the characteristics of ductile shear zone in mining area, we can find that the gold mineralization is obviously controlled by the shear zone. The regional ductile shear zones control the distribution of the ore deposit, while the secondary ductile brittle shear zones control the distribution of the gold ore bodies. The late brittle structure has some transformation and destruction to the ore body, and it also strengthens the gold once again to be enriched. The ductile shear zone is not only a guiding structure, but also a ore-controlling and host structure.Besides, for the study on the relationship between distribution of geochemical anomalies and fault zones, and the distribution of geochemical anomalies is obviously controlled by faults. As for a comparative study of geochemical profile and geological profile, the positions of shear zones and fault zones and the place of high Au content showed a corresponding relationship.Combine the macroscopic investigation of the field geology for it with its indoor geochemical analysis, the Ji Ziping gold deposits can be divided into 4 stages.